// AppleSignInManager.h
// 封装“用 Apple 登录”逻辑

#import <Foundation/Foundation.h>
#import <AuthenticationServices/AuthenticationServices.h>
@class UIViewController;

NS_ASSUME_NONNULL_BEGIN

/// Apple 登录回调结果
typedef void (^KBAppleSignInCompletion)(ASAuthorizationAppleIDCredential * _Nullable credential, NSError * _Nullable error);

/// AppleSignInManager 集中管理 Apple 登录流程与代理回调
@interface AppleSignInManager : NSObject <ASAuthorizationControllerDelegate, ASAuthorizationControllerPresentationContextProviding>

/// 单例便捷访问
+ (instancetype)shared;

/// 发起 Apple 登录
/// - 参数说明：
///   - presenting: 用于呈现授权界面的控制器
///   - completion: 主线程回调，返回凭证或错误
- (void)signInFromViewController:(UIViewController *)presenting completion:(KBAppleSignInCompletion)completion;

/// 根据已存储的 userIdentifier 检查凭证状态
/// 返回：ASAuthorizationAppleIDProviderCredentialAuthorized/Revoked/NotFound
- (void)checkCredentialStateWithCompletion:(void(^)(ASAuthorizationAppleIDProviderCredentialState state))completion;

/// 使用给定 userIdentifier 检查凭证状态（推荐：从服务端返回的 userIdentifier）
- (void)checkCredentialStateForUserID:(NSString *)userID completion:(void(^)(ASAuthorizationAppleIDProviderCredentialState state))completion;

/// 最近一次成功登录的 userIdentifier（已持久化）
@property (nonatomic, readonly, nullable) NSString *storedUserIdentifier;

/// 本地登出：清除已存储的 userIdentifier（不会向苹果撤销授权）
- (void)signOut;

@end

NS_ASSUME_NONNULL_END